A gas is contained in a vertical piston-cylinder assembly by a piston weighing 675 lbf and having a face area of 8 in.2 The atmosphere exerts a pressure of 14.7 lbf/in.2 on the top of the piston. An electrical resistor transfers energy to the gas in the amount of 3 Btu. The internal energy of the gas increases by 1 Btu, which is the only significant internal energy change of any component present. The piston and cylinder are poor thermal conductors and friction can be neglected. Determine the change in elevation of the piston, in ft.